The present application relates to semiconductor technology, and more particularly to a method of forming a semiconductor structure containing high germanium content silicon germanium alloy fins located on an insulator layer. The present application also relates to a semiconductor structure that is formed by the method of the present application.
For more than three decades, the continued miniaturization of metal oxide semiconductor field effect transistors (MOSFETs) has driven the worldwide semiconductor industry. Various showstoppers to continue scaling have been predicated for decades, but a history of innovation has sustained Moore's Law in spite of many challenges. However, there are growing signs today that MOSFETs are beginning to reach their traditional scaling limits. Since it has become increasingly difficult to improve MOSFETs and therefore complementary metal oxide semiconductor (CMOS) performance through continued scaling, further methods for improving performance in addition to scaling have become critical.
The use of non-planar semiconductor devices such as, for example, semiconductor fin field effect transistors (FinFETs), is the next step in the evolution of complementary metal oxide semiconductor (CMOS) devices. Semiconductor FinFETs can achieve higher drive currents with increasingly smaller dimensions as compared to conventional planar FETs.
Silicon germanium alloy fins having a germanium content of greater than 50 atomic percent are considered for 7 nm technology node and beyond. Achieving such high germanium content silicon germanium alloy fins on an insulator layer with conventional epitaxial growth and fin patterning for target fin widths are very challenging and is limited by various issues such as, for example, defectivity. Condensation is one approach that can be used to achieve high germanium content silicon germanium alloy fins however the non-uniform oxide removal from the sidewalls of the high germanium content silicon germanium alloy fins is very challenging resulting, in some cases, in fin detachment from the underlying insulator layer as well as too much insulator layer recess, which may cause a problem in subsequent processing steps.
In view of the above, there is a need for providing a method of forming high germanium content silicon germanium alloy fins on an insulator layer that avoids the drawbacks associated with the prior art mentioned above.